![background image](http://html.mh-extra.com/html/carrier/58mec/58mec_installation-start-up-and-operating-instructions-manual_2562805025.webp)
25
Upflow Furnaces
The return-air duct must be connected to bottom, sides (left or
right), or a combination of bottom and side(s) of main furnace
casing. Bypass humidifier may be attached into unused side
return air portion of the furnace casing. DO NOT connect any
portion of return-air duct to back of furnace casing.
Downflow and Horizontal Furnaces
The return-air duct must be connected to return-air opening
provided. DO NOT cut into casing sides or back to attach any
portion of return-air duct. Bypass humidifier connections should
be made at ductwork or coil casing sides exterior to furnace.
Step 5 -- Filter Arrangement
FIRE, CARBON MONOXIDE AND POISONING
HAZARD
Failure to follow this warning could result in personal injury
death, or property damage.
Never operate unit without a filter or with filter access
door removed.
!
WARNING
The air filter arrangement will vary due to application, furnace
orientation, and filter type. The filter may be installed in an
external Filter/Media cabinet (if provided) or the furnace blower
compartment. Factory supplied washable filters are shipped in the
blower compartment.
If a factory-supplied external Filter/Media cabinet is provided,
instructions for its application, assembly, and installation are
packaged with the cabinet. The Filter/Media cabinet can be used
with the factory-supplied washable filter or a factory-specified
high-efficiency disposable filter (see cabinet instructions).
If installing the filter in the furnace blower compartment,
determine location for filter and relocate filter retaining wire if
necessary. See Table 4 to determine correct filter size for desired
filter location. Table 4 indicates filter size, location, and quantity
shipped with this furnace. See Fig. 2 for location and size of
bottom and side return-air openings.
Table 4 –
Filter Information
AIR FILTER LOCATED IN BLOWER COMPARTMENT
FURNACE
CASING
WIDTH
IN (mm)
FILTER SIZE --- IN (mm)
FILTER
TYPE
Side Return†*
Bottom Return*
17–1/2
(445)
(1) 16 X 25 X 3/4
(406 X 635 X 19)
(1) 16 X 25 X 3/4
(406 X 635 X 19)
Washable
21 (533)
(1) 16 X 25 X 3/4
(406 X 635 X 19)
1) 20 X 25 X 3/4
(508 X 635 X 19)
Washable
24–1/2
(622)
(1 or 2)16 X 25 X 3/4
(406 X 635 X 19)
(1) 24 X 25 X 3/4
(610 X 635 X 19)
Washable
* Factory-provided with the furnace. Filters may be field modified by cutting
filter material and support rods (3) in filters. Alternate sizes and additional
filters may be ordered from your distributor or dealer.
† Upflow only. Alternate sizes and additional filters may be ordered from
your dealer.
FILTER
RETAINER
WASHABLE
FILTER
A93045
Fig. 26 -- Filter Installed for Side Inlet
WASHABLE
FILTER
FILTER
SUPPORT
FILTER
RETAINER
17
1
⁄
2
-IN. (444mm) WIDE
CASINGS ONLY:
INSTALL FIELD-SUPPLIED
FILTER FILLER STRIP
UNDER FILTER.
1
″
24
1
/
2
″
3
″
21-IN. (533mm) WIDE
CASINGS ONLY:
SUPPORT RODS (3)
EXTEND 1/4" (
6
mm) ON
EACH SIDE OF FILTER AND
REST ON CASING FLANGE
(76mm)
(533mm)
(25.4mm)
A00290
Fig. 27 -- Bottom Filter Arrangement
58MEC